login
Numbers of the form 9^x-y^2 >= 0.
1

%I #9 May 14 2017 22:48:34

%S 0,1,5,8,9,17,32,45,53,56,65,72,77,80,81,104,153,161,200,245,288,320,

%T 329,368,405,440,473,477,485,504,533,560,585,608,629,632,648,665,680,

%U 693,704,713,720,725,728,729,785,936,968,1085,1232,1377,1449,1457,1520

%N Numbers of the form 9^x-y^2 >= 0.

%t max = 2000; Clear[f]; f[m_] := f[m] = Select[Table[9^x - y^2, {x, 0, m}, {y, 0, Ceiling[9^(x/2)]}] // Flatten // Union, 0 <= # <= max &]; f[1]; f[m = 2]; While[f[m] != f[m - 1], m++]; Print["m = ", m]; A051219 = f[m] (* _Jean-François Alcover_, May 14 2017 *)

%K nonn

%O 1,3

%A _David W. Wilson_